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The aerodynamic performance of paragliders

Published online by Cambridge University Press:  04 July 2016

H. Babinsky
H. Babinsky*
Affiliation:
Engineering DepartmentUniversity of CambridgeCambridge, UK
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Abstract

An analysis of paraglider performance has revealed that wing section drag is the most significant contribution to overall drag. Wind tunnel measurements performed on two-dimensional hollow models indicate that intake drag is less significant than previously thought. An experimental investigation into the characteristics of a ‘quasi ’ -two-dimensional flexible model consisting of solid ribs covered with a fabric skin was performed at realistic Reynolds numbers. The main cause of performance deterioration was found to be a significant reduction in section lift coefficient when compared to a similar solid wing section. This is believed to be mainly due to two factors: a large trailing edge separation and the deformation of the wing between ribs. The deformation was measured and it was shown that the deformed shape is less capable of generating high lift coefficients than the design section. It is thought that the extent of the trailing edge separation is increased due to the presence of streamwise grooves caused by the shape deformation of the wing. The shape of the separated region was found to be strongly three-dimensional with the separation point being about half a chord-length further upstream along the ribs. A small separation bubble was also observed immediately behind the lip of the intake, due to the fabric ‘flaring’ open. Based on the observations presented a number of suggestions for improved wings have been made.

Type
Research Article
Information
The Aeronautical Journal , Volume 103 , Issue 1027 , September 1999 , pp. 421 - 428
Copyright
Copyright © Royal Aeronautical Society 1999 

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References

1. Rogallo, F.M., Lowry, J.G., , Croom, D.R. and Taylor, R.T. Preliminary investigation of a paraglider, NASA TN D-443, 1960.Google Scholar
2. Polhamus, E.C. and Naeseth, R.L. Experimental and theoretical studies of the effects of camber and twist on the aerodynamic characteristics of parawings having nominal aspect ratios of 3 and 6, NASA TN D-972, 1963.Google Scholar
3. Nielsen, J.N., Kriebel, A.R. and Goodwin, F.K. Theoretical aerodynamics of one-lobed flexible parawings at low speeds, J Aircr, March-April 1965, 2, (2).Google Scholar
4. Burk, S.M. and Ware, G.M. Static aerodynamic characteristics of three ram-air-infiated low-aspect-ratio fabric wings, NASA TN D-4182, 1967.Google Scholar
5. Lingard, J.S. The aerodynamics of gliding parachutes, AIAA 86-2427, Proceedings 9th Aerodynamic Decelerator and Balloon Technology Conf, Albuquerque, October 1986.Google Scholar
6. Nicolaides, J.D. Parafoil Wind Tunnel Tests, Wright-Patterson Air Force Base, Tech Rep AFFDL-TR-70-146, June 1971.Google Scholar
7. Ware, G.M. and Hassell, J.L. Wind tunnel investigation of ram-air inflated all flexible wings of aspect ratios 1·0 to 3·0, NASA TM SX- 1923, 1969.Google Scholar
8. Hoerner, S.F. Fluid Dynamic Drag, New York, 1965.Google Scholar
9. Walpert, R.A. and Kyle, C.R. Aerodynamics of the human body in sports, J Biomechanics, 1989, 22, (10), pp 1096–1100.Google Scholar
10. Massey, B.S. Mechanics of Fluids, 6th ed, Chapman & Hall, 1989.Google Scholar
11. Burnell, S. PhD Thesis, Cambridge University, Engineering Department, Cambridge, 1997.Google Scholar
12. Busto, E. Cloud Base: Aspect Ratio and Induced Drag (translated by Coates, M.), Delta and Parpendio, July, 1994.Google Scholar
13. Speelman, R.J., Babish, C.A. and Berndt, R.J. Para-foil steerable parachute, exploratory development for airdrop system application, USAF Flight Dynamics Lab, Ohio, AFFDL-TR-71-37, 1972.Google Scholar
14. Hepperle, M. Analyze an Airfoil, http://beadecl.ea.bs.dlr.de/Airfoils.Google Scholar